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Bio 2.3 Demonstrate understanding of adaptation of plants or animals to their way of life

-> taxonomy-> wideshot of systems and diversity-> adaptations-> insects, mammals and fish-> review/ making connections

PhylogeneticsCoz life is amazing but can be hard to get your head around

Kingdom: AnimaliaPhylum: ChordatesClass: Mammals

Order: PrimatesFamily: Homininsgenus: HomoSpecies: sapiens

Phylum Cnidaria

Phylum Mollusca

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Arthropoda

Mission: Make a mnemonic

• Kingdom

• Phylum

• Class

• Order

• Family

• Genus

• Species

This unit we will be focussing on 3 taxonomic groups.

Phylum Arthropoda – Class insecta

• jointed limbs

• three pairs of legs

• often have wings

• compound eyes

• Tracheal gas exchange

Phylum Chordata – Class Fish (Pisces)

• Aquatic

• Scales (usually)

• Gills for gas exchange

• Closed blood system

Phylum Chordata – Class Mammalia

• Young are fed milk

• Hairy not furry

• Large brain

• 3 groups – Monotremes, Marsupials

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Adaptation

An adaptation is…

The adjustment of behaviour or physiology of an organism to become more suited to their environment and lifestyle.

Why adapt?

To survive!

An environment tends to eliminate living things that are not suited to it. A plant that was not adapted to conserve moisture would soon die in the desert.

“According to Charles Darwin's theory of evolution by natural selection, the organisms adapt to their environment to become better fitted to survive and passing their genes on to the next generation. “

Adapting to look like something you’re not

Adapting to the cold Adapting to the heat

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People do it too Adjusting to different air supply issues

In order to operate in extreme environments, some animals have evolved different types of blood composition: the sperm whale and the bar-headed goose of Asia. Both these species have an uncanny ability to store a lot more oxygen in their blood cells than other animals.

Like a fish that can breathe air

• In tropical and equatorial areas• Massive seasonal changes in water levels• Lungfish (Dipnoi) create a mucus sack to

protect themselves through the drought.• Some species of catfish and eel not only

breathe air, but also travel on land between pools.

• Take oxygen from the air through the use of a specialized area of their intestines.

…and some species get really clever….

Gas exchange + Respiration + Breathing

Your mission

• What is the purpose of gas exchange?

• Name the respiratory gases

• How are gasses exchanged with the environment?

• Contrast air and water in terms of the challenges they present for gas exchange

1. What is the purpose of gas exchange?

The purpose of gas exchange is to exchange oxygen and carbon dioxide with the atmosphere.

Oxygen is required by all the cells of the body for respiration, the process in which energy is extracted from the glucose in the food an animal eats. The waste products of respiration are CO₂ and water.

CO₂ leaves the body through the same process that oxygen is absorbed, only in reverse. Gas exchange absorbs O₂ from the environment and releases CO₂.

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2. Name the respiratory gasses

• O₂ / Oxygen

• CO₂/ Carbon dioxide

3. How are gases exchanged with the environment?

Gases are exchanged with the environment through the process of diffusion. First the gasses in the environment need to reach the surfaces across which diffusion can occur, this usually happened via breathing.

• Diffusion across a semi-permeable membrane and into the body

Transport system to the cells

Transport of waste products out of the body

Features of a gas exchange surface

4. Contrast air and water in terms of the challenges they present for gas exchange

• O₂ content is higher in air than water

• What does this mean for the animal ?(Size of GE surfaces, Energy consumption, efficiency of the process).

• In the water surfaces are less likely to dry out (what mechanisms do land animals need to prevent this?)

Situations where the rule is different – high altitude or stagnant water, and what this means for the animal (Lower energy use, ability to store O₂ etc…).

Your mission• Read ‘Gas exchange’ page 211

Write definitions for:1. Respiration2. Gas exchange3. Breathing4. DiffusionConsider the role of each of these in gas exchange for an organism

• Do question 1 on page 217• Read ‘mammals” and “Breathing” 214-217

How is the air up there?

Mountain Altitude Oxygen content

Sea level 0m ~20%

Mt Cook 3,724 m ~13%

Tibetan plateau 4,000m ~12%

Kilimanjaro 5,791m ~10%

Mt Everest 8,839m ~6.8%

Oxygen in the air can be affected by altitude and temperature. Higher altitude = less dense = less oxygen molecules in a breathWarmer = less dense = less oxygen molecules in a breath

http://www.higherpeak.com/altitudechart.html

What does it mean?

• Mountain climbers need specialised breathing equipment at very high altitudes

• Over time the human body can adapt to some changes:

haemoglobin concentrations

Heart rate

• And some people are equipped to adapt better than others

http://www.nature.com/ng/journal/v46/n9/abs/ng.3067.html

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Animals that live at high altitudes

Bar headed goose

• Higher lung capacity

• Higher heart rate

• Alt 7,000m+

• Short term acclimatisation

Tibetan Yak• Larger lungs and heart• More efficient transport of

O₂• More efficient metabolism• 3,000 - 5,000m• Long term adaptation

Animals that need more oxygen

Big: Elephant

• Breathes 310L air/ minute (6 in Humans)

• Huge lungs!

• Where are the lungs? How are they housed?

How are they held up?

• Circle of skin separating trunk from lungs.

• Need to drink lots!

Animals that need more oxygen

Fast: Cheetah

• Fastest land animal (120km/hr)

• Takes lots of energy

• Enlarges nostrils, sinuses, lungs,

• Enlarged heart = increased blood flow

• 60-150 breaths per minute (2x humans)

• Fast muscles don’t store oxygen well = need a good supply

Your mission

Use your books (pg211 onwards) and what we have discussed today to make notes on the following

1. List the features required for diffusion

2. Describe the gas exchange system of a mammal.

3. Describe one case in which this system may need to be specialised (adapted). Include how the system is specialised and relate it to the environmental conditions it is specialised to.

Dissection of a cow pluck:

Observe • Thin• Moist • Large surface area

• Trachea• Bronchus, bronchiole• Rings of cartilage• Lung• Alveoli• And consider how it relates

to the circulatory system

Draw a diagram of a mammal gas exchange system.

• Include the features you observed

• Annotate your diagram with how some of these features are adapted to a mammals way of life

• Refer to 214-216 in your textbook for more info

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Thinking points

• What are the features required of a gas exchange system?

• Why are the lungs so bloody?

• Any adaptations of a mammal system to help them with gas exchange?

• Annotated diagram of a mammal respiratory system – what is an annotated diagram?

Have you?

1. Listed the features required for diffusion.

2. Describe the gas exchange system of a mammal.

3. Describe one case in which this system may need to be specialised (adapted). Include how the system is specialised and relate it to the environmental conditions it is specialised to.

Gas exchange in insects

https://www.youtube.com/watch?v=wMbi_NcI2JY

Spiracles

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Read page 212 – “gas exchange in insects”Do question 7 on page 217

Paragraph format including:

• Advantages

• Disadvantages/ limitations

• Similarities

• Differences

Insects breathe air….usually

-> So what are your options if you breathe air but live in the water?

-> What are the advantages/ disadvantages?

http://www.npr.org/sections/krulwich/2012/02/24/147367644/six-legged-giant-finds-secret-hideaway-hides-for-80-years?sc=fb&cc=fp

Silly science Friday

• https://www.youtube.com/watch?v=yejDghqigW0 – Breathing underwater

• https://www.youtube.com/watch?v=YtryV9qItsg - freediving

• http://www.sciencealert.com/watch-the-truth-about-toilet-swirl

• https://www.youtube.com/user/tomcfad - science rapping

• https://www.youtube.com/watch?v=IhJQp-q1Y1s – fish slapping

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Gas exchange in fish

Gas exchange in fish

• How do fish breathe?

• Support?

• Red?

• Protection?

• Moisture?

• Flow?

• Efficiency?

• Counter current gas exchange

• Just keep swimming – grey nurse

Counter current gas exchange

Read “Gas exchange in fish” pg 213 and 214

• Do question 8

Paragraph format including:

• Advantages

• Disadvantages/ limitations

• Similarities

• Differences

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Circulatory systems and oxygen transport

Insects Fish Mammals

Open circulatory system Closed circulatory system Closed circulatory system

Oxygen not transported in the circulatory system

Single system• Blood travels from the heart to the

gills, then to the body and back to the heart.

• Blood looses pressure being pushed through the capillaries in the gills.

• Not as efficient

Double system• Blood travels from the heart to the

lungs and back to the heart before being pumped around the body.

• Blood looses pressure being pushed through the capillaries at the alveoli.

• Blood regains high pressure at the heart before being pumped to the body = good at delivering O₂ to high demand body systems

Haemolymph Blood Blood

Gas exchange in fish: Dissection

*Observe

• Operculum

• Gills

• Gill arches

• Gill filaments

• Gill lamellae

• Gill rakers

• Path of water flow

* Draw a diagram of a fish gas exchange system.

• Include the features you observed

• Annotate your diagram with how some of these features are adapted to a fish’s way of life

• Refer to 213- 214 in your textbook for more info

*Think:

• Thin

• Moist

• Large surface area

• Concentration gradient

Gas exchange in Insects: Dissection

*Observe

• Spiracles

• Trachea

• Tracheoles?

* Draw a diagram of an Insect gas exchange system.

• Include the features you observed

• Annotate your diagram with how some of these features are adapted to an insects way of life

• Refer to 212 - 213 in your textbook for more info

*Think:

• Thin

• Moist

• Large surface area

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RevisionTest is next week

You will have 2 lessons to complete the test

It requires you to answer both long and short form questions

You can (and we encourage you to) illustrate your explanations with diagrams

Make the connections – link structure to function. Compare andcontrast structures and animal groups.

Revision – what’s your strategy?

• Do questions 2- 6

• Do questions 9-10

• Use revision sheet to study key points and memorise definitions.

• Use cut and order activity to organise ideas and write descriptions of gas exchange systems.

• Make flashcards to memorise definitions and key points.

• Draw and annotate diagrams of Mammal, Fish and Insect respiratory systems.

• Make a table to compare and contrast systems.

Compare and contrast key points – AND relate structure to function/ need

Mammals Fish Invertebrates

Lungs + Circulatory system Gills + Circulatory system Tracheal tubes

Diffusion of O₂ across a large moist surface

√ √

O₂ has to dissolve then diffuse• Must keep surface moist

X √

High O₂ in air (~20%) Low O₂ in water (~1%) High O₂ in air (~20%)

Closed, double circulatory system Closed single circulatory system Open circulatory system

Efficient at transporting O₂ to the cells

Efficient at getting O₂ from water Mostly passive – not very efficient.